Evaluation of the Central Nervous System Flashcards
What is the lumbar puncture (LP) useful for?
It’s helpful to obtain the cerebrospinal fluid (CSF); making it useful to diagnose:
- meningitis
- encephalitis
- subarachnoid hemorrhage
Define meningtitis
Inflammation in the subarachnoid space
What Sx triad occurs in meningitis?
nuchal rigidity, mental status change, and fever
What is the clinical utility for CSF gram stain and culture?
It’s helpful for the rapid and accurate diagnosis for bacterial meningitis
- takes 24-48 hrs for the results to come in
Should antibiotics be given to patients before cultures are taken?
No, because it could decrease the likelihood of isolating pathogen
Would a gram stain show up positive or negative for viral/fungal meningitis?
Negative
What is the purpose for polymerase chain reaction (PCR)?
Its main use is to diagnose viral CNS infection
- Has a high sensitivity and specificity
Who am I?
Used to obtain CSF; can assess opening pressure; Safety: cerebral herniation
Lumbar puncture
What is electroencephalography’s function?
Monitors the electrical activity of the brain
What is 1 of the clinical utilities for electroencephalography (EEG)?
to differentiate seizures
What is electromyography’s (EMG) function?
To measure muscle activity in response to nerve stimulation
What is 1 of the clinical utilities for EMG?
To identify muscle disease
What is the nerve conduction velocities (NCVs) function?
To measure nerve stimulation
To detect the presence of localized peripheral nerve injuries
What are the 2 clinical utilities for NCVs?
To identify carpal tunnel syndrome/myasthenia gravis
To safely have a low-risk; pacemaker - modify electrode position
Who am I?
Used to assess electrical activity of the brain; can differentiate seizure etiology; safety: noninvasive, low risk
Electroencephalography (EEG)
What is the function of a computed tomography (CT)?
It combines serial X-rays via computer processing
It’s essentially used in focal neurologic findings
What are 2 important clinical utilities in a CT?
To differentiate cerebral infarction vs. hemorrhage
It’s negative/positive outcomes: risk of radiation (+), and some contrast
What is the function of a magnetic resonance imaging (MRI)?
It uses magnetic properties of the Hydrogen atom
- Has improved anatomic accuracy compared to CT
- It might be ineligible for patients with metal implants
What is 1 clinical utility for MRIs?
It’s positive (safe) outcome is it has a low risk of radiation (-)
What is the function of a Magnetic Resonance Angiography (MRA)?
Same function as MRI
- HOWEVER, it’s essentially used in cerebral circulatory evaluation, such as:
- Intracranial disease
Who am I?
Used to assess status of the cerebral vasculature, identify intracranial disease; Safety: (-) radiation risk, (~) contrast
Magnetic Resonance Angiography (MRA)
What is a Positron Emission Topography’s (PET) function?
To assess regional metabolic changes in the brain
- Essentially used for Extracranial metastatic disease
What is 1 clinical utility for PET scans?
To identify Alzheimer’s disease
What is the function of a Single-Photon Emission Computed Tomography (SPECT)?
To uptake radionucleotide (e.g., radiotracer)
What is 1 clinical utility for a SPECT scan?
To identify cerebral ischemia and dementia
